The present invention relates to an apparatus for facing the ends of tubular articles such as steel pipes, and more particularly to an apparatus for performing each of the operations of cutting, bevelling and deburring the end of a pipe at a single location.
The cutting and trimming of steel pipe typically involves the operations of first cutting a segment off the end of the pipe to bring the pipe to a specified length. The cut is generally made in a direction perpendicular to the axis of the pipe so that the cut edge of the pipe is relatively square. Thereafter, a bevel is provided in the cut edge of the pipe, for example to provide a design that more readily facilitates welding of pipes to one another in an end-to-end relationship. The bevelling operation can result in a burr being produced on the interior edge of the pipe wall, which must be removed so that two pipes can be readily joined. The deburring operation typically involves placing a deburring knife within the interior of the pipe and moving it in a radially outward direction to trim the cut edge of the pipe from the inside out.
In the past, these operations have typically been performed by cutting tools that are mounted in stationary positions, and the cutting operations are performed by rotating the pipe about its longitudinal axis while advancing the cutting tools into engagement therewith. A major disadvantage associated with this type of operation results from the fact that pipes of substantial length, for example in the range of 16-60 feet, are rarely perfectly linear. Thus, if the pipe is rotated so that the end being trimmed rotates about a stationary axis, the remote end of the pipe can travel in a relatively wide circular path. This type of motion can result in the remote end of the pipe being banged against support structure, thereby leading to wear of the support structure and possible damage to the pipe. In addition, the centrifugal forces generated by the rotation of the remote end and the banging of the pipe set up vibrations at the end of the pipe that is being trimmed, which can lead to premature wear and even breakage of the cutting tools.
Accordingly, it is a general object of the present invention to provide a novel pipe facing apparatus in which the pipe is held in a stationary position during the facing operations so that nonlinearity of the pipe will not have any effect upon rotary motion required for the various facing operations.
It is another object of the present invention to provide a novel pipe facing apparatus of this type that is capable of carrying out each of the operations of cutting, bevelling and deburring at a single location, to thereby decrease the number of separate processing steps that a pipe is required to undergo during a facing operation.
It is a further object of the present invention to provide a novel pipe facing apparatus that advances one or more rotating cutting tools in a radial direction into engagement with a pipe to cut the same, and then simultaneously advances a bevelling tool and a deburring tool in a radial direction as the cutting tool is being withdrawn, to bevel the pipe end during radially inward advancement of the tools and deburr the pipe end during subsequent radial outward withdrawal.
The manner in which the present invention achieves these objects, as well as their attendant advantages, can be best appreciated by reference to the following detailed description of the preferred embodiment of the invention illustrated in the accompanying drawings.